The cherub is a monster new to the Doom universe, having not appeared in older titles. It has the appearance of a human baby with insect-like wings (which produce a characteristic insect buzzing sound when in action), solid black eyes and arms terminating in monstrous sharp claws. It has no legs, having instead the hind quarters of a fly. It emits sounds similar (but distorted) to a baby babble.

Cherubs typically attack in groups, with the player fighting a series of several of them in the same area. However, cherub groups are typically smaller than Trite or Tick swarms, and they usually attack the player 2 or 3 at a time instead of several at once.

Cherubs are often found near Mancubi, leading some to think that cherubs could be their offspring.

The cherub is one of the weakest demons in the game, although it is more powerful than the other small "pest"-type demons such as the Lost Soul, the Trite and the Tick. Its power should not be underestimated, as it is able to use its wings to strike a blow very accurately, which makes it hard to dodge. It uses its insect-like claws to blind the enemy.

Cherubs move with a combination of crawling along the ground and using their wings to quickly hover forward several feet. They attack by quickly leaping at the player from a significant distance away, and have a noticeably further attack range than Trites or Ticks.

While weak, the cherub can be difficult to hit thanks to its small size, and players often misjudge how far it can actually leap. It is strongly advised to keep a good distance from it and hammer it to pieces from afar with the machinegun. In Resurrection of Evil, the cherub can be picked up and launched by the Grabber, which is instantly fatal to it. As they come in large numbers, it is advised to utilize rapid-firing weapons to dispatch them all quickly.